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星形超曲面上Hamilton系统Brake轨道的多重存在性 被引量:1
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作者 安天庆 《兰州大学学报(自然科学版)》 CAS CSCD 北大核心 2004年第6期9-12,共4页
研究Hamilton系统具有固定能量的brake轨道的个数问题.在适当条件下,证明了R2n中紧星 形超曲面∑上brake轨道的几个多重存在性定理,结果包含了Szulkin的已有结论.
关键词 星形超曲面 brake轨道 Szulkin指标 临界点
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正定型超曲面上Hamilton系统Brake轨道的存在性
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作者 安天庆 叶国菊 《河海大学学报(自然科学版)》 CAS CSCD 北大核心 2005年第5期602-606,共5页
结合Rabinowitz和Szulkin关于Brake轨道的存在性与多重性的结论,利用部分对称泛函的临界点理论研究Hamilton系统在更广泛的能量面上Brake轨道的存在性问题.在适当条件下,证明了R2n中正定型超曲面Σ上存在Hamilton系统的Brake轨道.由于... 结合Rabinowitz和Szulkin关于Brake轨道的存在性与多重性的结论,利用部分对称泛函的临界点理论研究Hamilton系统在更广泛的能量面上Brake轨道的存在性问题.在适当条件下,证明了R2n中正定型超曲面Σ上存在Hamilton系统的Brake轨道.由于星型超曲面是正定型超曲面的特殊情形,该研究包含了Rabinowitz的相应结论. 展开更多
关键词 正定型超曲面 brake轨道 Szulkin指标 临界点
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Computer aided design and analysis of a tunable muzzle brake 被引量:11
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作者 Ekansh Chaturvedi Ravi K.Dwivedi 《Defence Technology(防务技术)》 SCIE EI CAS CSCD 2019年第1期89-94,共6页
This research work deals with the design of a tunable muzzle brake [10] for a rifle chambered in 5.56 x 45 NATO ammunition. It proposes to solve the problem of handling differences from shooter to shooter by incorpora... This research work deals with the design of a tunable muzzle brake [10] for a rifle chambered in 5.56 x 45 NATO ammunition. It proposes to solve the problem of handling differences from shooter to shooter by incorporating the feature of tunability. Beside this, it also solves the problem of requirement of optimum recoil in short recoil weapons. This innovation gives this design an edge over its already existing counterparts in the market. The product is designed using the internal ballistics calculations and the investigations been performed using solidworks flow simulation tool and ANSYS static structural to check the parameters like velocity distribution, pressure growth, and muzzle brake force along the series of ports and comparison of the so found results with those devised by the authors of the documents mentioned in references. This assures the market adaptability of the product for satisfactory performance, when brought among its already existing counterpart, though with a slight edge over them due to tunability. The results so found shall be concluded satisfactory regarding the performance of muzzle brake. 展开更多
关键词 Flow simulation INNOVATION MUZZLE brake TUNABILITY Set SCREWS
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Transient Temperature Field Analysis of Brake in Nonaxisymmetric Three-dimensional Model 被引量:11
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作者 GAO Chen-hui, LIN Xie-zhao (Department of Mechanical Engineering, Fuzhuo University, Fuzhou 35000 2, China) 《厦门大学学报(自然科学版)》 CAS CSCD 北大核心 2002年第S1期164-,共1页
The disk-pad brake used in automobile is divided i nt o two parts: the disk, geometrically axisymmetric, and the pad, of which the geo metry is three-dimensional. In the course of braking, all parameters of the pro ce... The disk-pad brake used in automobile is divided i nt o two parts: the disk, geometrically axisymmetric, and the pad, of which the geo metry is three-dimensional. In the course of braking, all parameters of the pro cesses (velocity, load, temperature, physicomechanical and tribological characte ristics of materials of the couple, and conditions of contacts) vary with the ti me. Considerable evidence has show that the contact temperature is an integral f actor reflecting the specific power friction influence at the combined effect of load, speed, friction coefficient, thermo physical and durability properties of materials of a frictional couple. Furthermore, the physic mechanical state of t he interface of the disk and pads is determined not only by the contact temperat ure but also by the nonstationary temperature field. Using the two-dimensional model for thermal analysis implies that the contact conditions and frictiona l heat flux transfer are independent of θ. This may lead to false thermal elast ic distortions and unrealistic contact conditions. An analytical model is presen ted in this paper for the determination of contact temperature distribution on t he working surface of a brake. To consider the effects of the moving heat source (the pad) with relative sliding speed variation, a transient finite element tec hnique is used to characterize the temperature fields of the solid rotor with ap propriate thermal boundary conditions. And the transient heat conduction problem can be solved as a nominal 3-D transient heat transfer problem with an immovab le heat source. Numerical results shows that the operating characteristics of th e brake exert an essentially influence on the surface temperature distribution a nd the maximal contact temperature. The temperature field presents a noaxisymmet ric characteristic (a function of θ) and proves to be strongly localized and po ssesses a sharp gradient in both axial and radial directions. 展开更多
关键词 disk-pad brake nonaxisymmetric temperature fiel d frictional heat FEM
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Numerical research on adverse effect of muzzle flow formed by muzzle brake considering secondary combustion 被引量:9
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作者 Peng-fei Li Xiao-bing Zhang 《Defence Technology(防务技术)》 SCIE EI CAS CSCD 2021年第4期1178-1189,共12页
The simulation of the artillery interior and intermediate ballistics problem is performed to investigate the influence of a gas dynamics device,muzzle brake,on the muzzle hazard phenomena,such as flash and blast waves... The simulation of the artillery interior and intermediate ballistics problem is performed to investigate the influence of a gas dynamics device,muzzle brake,on the muzzle hazard phenomena,such as flash and blast waves.The correlation of the chemical reactions with the characteristics of the muzzle flow field is analyzed by the simulation for a further understanding of the secondary combustion phenomenon of the muzzle flow.The novel structure of muzzle flow caused by the muzzle brake is presented by the simultaneous solution of the interior ballistics model and multi-species Navier-Stokes equations in order to analyze the influence of the muzzle brake structure on the chemical reactions.The secondary combustion of the muzzle flow due to the oxygen-supplement chemical reactions is obtained by the chemical reaction kinetic model.The interaction of the blast waves released from the muzzle brake is illustrated in detail and the mechanism of the formation of muzzle flash is analyzed.This research provides a reference for the studies on the suppression of the muzzle flash. 展开更多
关键词 Muzzle flow Muzzle brake Secondary combustion Chemical reaction
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Analysis and Design of Cylindrical Magnetorheological Fluid Brake 被引量:3
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作者 HUANG Jin, ZHANG Jun-qian, YANG Yan (Department of Engineering Mechanics, Chongqing University, Chongqing 400044, China) 《厦门大学学报(自然科学版)》 CAS CSCD 北大核心 2002年第S1期27-28,共2页
Magnetorheological (MR) fluids consist of stable suspensions of magnetic particles in a carrying fluid such as water or silicone oils. The magnetorheological response of MR fluids results from the polarization induced... Magnetorheological (MR) fluids consist of stable suspensions of magnetic particles in a carrying fluid such as water or silicone oils. The magnetorheological response of MR fluids results from the polarization induced in suspended particles by application of an external magnetic field. The interaction between the induced dipoles causes the particles to form columnar structure, parallel to the applied field. These chain-like structures restrict the motion of fluids, thereby increasing the viscosity and yield stress of the MR fluids. These mechanical characteristics allow for the construction of magnetically controlled device such as the MR fluids rotary brakes. However, there has been little information published about the design of MR fluid brakes. In this paper the design of the cylindrical MR fluid brake is investigated theoretically. Bingham model is used to characterize the constitutive behaviors of the MR fluids subject to an external magnetic field. The operational principle of the cylindrical MR fluid brake is presented. The theoretical method is developed to analyze the transmission properties of the torque of the cylindrical MR fluid brake. An engineering expression for the torque is derived to provide the theoretical foundations in the design of the cylindrical MR fluid brake. Based on this equation the volume and thickness of the annular MR fluids within the brake is expressed as functions of the desired ratio of torques with saturated magnetic field and without external field, the controlled mechanical power and the MR fluid material properties. The parameters of the thickness and width of the fluid in the brake can be calculated from the obtained equations when the required mechanical power level, the desired torque ratio are specified. 展开更多
关键词 MR fluids brake analysis method design method
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Dynamic performance of six-axle locomotive subjected to asymmetric brake shoe forces 被引量:2
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作者 LIU Peng-fei ZHANG Kai-long CAO Yun-qiang 《Journal of Central South University》 SCIE EI CAS CSCD 2020年第9期2776-2791,共16页
To research the influence of asymmetric brake shoe forces(ABSF)induced by braking failure on the dynamic performance of six-axle locomotive,the static equilibrium model of three-axle bogie and dynamic model for locomo... To research the influence of asymmetric brake shoe forces(ABSF)induced by braking failure on the dynamic performance of six-axle locomotive,the static equilibrium model of three-axle bogie and dynamic model for locomotive are established.The coupling vibration equations of axle hung motor and wheelset are derived.For the air braking,the influence mechanism of ABSF on the wheel-rail asymmetric motion and force characteristics are discussed.It can be found that if the ABSF is applied in the front wheelset,all the wheelsets move laterally in the same direction.Once the ABSF occurs in the middle or rear one,other wheelsets may move laterally towards the opposite direction.The motion amplitude and direction of all wheelsets strictly depend on the resultant moment of suspension yawing moment and brake shoe asymmetric moment.For the asymmetric braking,the free lateral gap of axle-box could increase the wheelset motion amplitude,but could not change the moving direction.In both the straight line and curve,the ABSF may lead to wheelset misaligning motion,intensify the wheel-rail lateral dynamic interaction and deteriorate wheel-rail contact state.Especially for the steering wheelsets,the asymmetric braking increases the wheelset attack angle significantly,which forms the worst braking condition. 展开更多
关键词 LOCOMOTIVE brake shoe force dynamic performance asymmetric braking wheel-rail contact
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Dynamic mechanical characteristics of NdFeB in electromagnetic brake 被引量:2
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作者 Lei Li Guo-lai Yang Li-qun Wang 《Defence Technology(防务技术)》 SCIE EI CAS CSCD 2023年第1期111-125,共15页
With the continuous development of artillery,the disadvantages of hydraulic recoil brakes gradually appear.At the same time,the appearance of high-performance Nd Fe B permanent magnet makes it possible to apply electr... With the continuous development of artillery,the disadvantages of hydraulic recoil brakes gradually appear.At the same time,the appearance of high-performance Nd Fe B permanent magnet makes it possible to apply electromagnetic braking technology to recoil mechanism.In this paper,prototype tests of a certain artillery were carried out to verify the feasibility of the electromagnetic brake(EMB)and obtain the electromagnetic braking force.Due to the brittleness of Nd Fe B,in order to eliminate the worry about the safety of EMB,SHPB experiments of Nd Fe B were carried out.Then,based on the assumption of uniform crack distribution,the law of crack propagation and damage accumulation was described theoretically,and the damage constitutive model suitable for brittle materials was proposed by combining the Zhu-Wang-Tang(ZWT)equation.Finally,the numerical simulation model of the artillery prototype was established and through calculation,the dynamic mechanical characteristics of Nd Fe B in the prototype were analyzed.The calculation results show that the strength of Nd Fe B can meet the requirements of the use in the working process.From the perspective of damage factor,the damage value of the permanent magnet on the far right is larger,and the damage value of the inner ring gradually decreases to the outer ring. 展开更多
关键词 Electromagnetic brake Sintered NdFeB Damage constitutive Dynamic mechanical characteristics
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Preparation and characteristics of C/C composite brake disc by multi-cylindrical chemical vapor deposition processes 被引量:3
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作者 袁毅东 张富宽 周万成 《Journal of Central South University of Technology》 EI 2005年第4期400-402,共3页
The C/C composite brake discs were prepared by tri-cylindrical chemical vapor deposition (CVD) process. The optimum processing parameters were as follows: deposition temperature was 830 - 930 ℃, the gas- flow rate... The C/C composite brake discs were prepared by tri-cylindrical chemical vapor deposition (CVD) process. The optimum processing parameters were as follows: deposition temperature was 830 - 930 ℃, the gas- flow rates of N2 and propylene were 4.8 - 5.2 m^3/h and 5.8 - 6.2 m^3/h, respectively, the furnace pressure was 4.5 - 5.5 kPa and the deposition time was 200 h. The effects of processing parameters on the densified rates, thermal-physical property and mechanical performance of C/C composite brake discs were studied. The results show that density, heat conductivity, bend strength and abrasion ratio of the multi-cylindrica brake discs are 1. 02 - 1. 78 g/cm^3 , 31 W/(m·K), 114 MPa and 7μm/s, respectively, which are approximately similar to those of the singlecylindrical ones. The gas tlow rate has no relation to the number of the cylinder and furnace loading. The utilization ratio of carbon can be improved by multi-cylinder CVD process without changing the characteristics of brake disc. 展开更多
关键词 C/C composite brake disc chemical vapor deposition multi-cylindrical mechanical property
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Investigations on influence of rifle automatics system action on values of energetic efficiency coefficient of muzzle brakes 被引量:1
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作者 Radoslaw Trebinski Zbigniew Leciejewski +2 位作者 Jacek Kijewski Dawid Gozdzik Damian Szupienko 《Defence Technology(防务技术)》 SCIE EI CAS CSCD 2022年第10期1741-1747,共7页
The objective of the paper was to compare values of the muzzle brake efficiency coefficient for a rifle with active or inactive automatics systems.Special laboratory stand designed for investigating the recoil process... The objective of the paper was to compare values of the muzzle brake efficiency coefficient for a rifle with active or inactive automatics systems.Special laboratory stand designed for investigating the recoil process was used.The motion of the rifle was detected by the use of the laser interferometer and the optical camera.The recoil velocity time courses were determined by smoothing and differentiation of experimental position records.The results of the experiments indicated that in the case of an active automatics system two values of the recoil velocity can be used for calculation of the energetic efficiency coefficient:the maximum recoil velocity and the final recoil velocity at the end of the automatics action cycle.The values of the coefficient,calculated using these two values of the recoil velocity,distinctly differ.However,it was shown that their values indicate the same relation between the efficiency of various muzzle brakes.The value of the efficiency coefficient,determined on the basis of the final recoil velocity value,is practically the same as that determined on the basis of the final recoil velocity value for the rifle with an inactive automatics system. 展开更多
关键词 BALLISTICS Muzzle brakes Automatic rifle Efficiency Recoil velocity
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FastBrake电空制动控制系统 被引量:6
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作者 姜祥禄 高连东 《铁道机车车辆》 北大核心 2009年第5期48-51,共4页
介绍了西屋制动公司FastBrake电空制动控制系统的主要构成、综合作用等。并对FastBrake在中国的应用提出了几点建议。
关键词 Fastbrake 西屋 电空制动 制动系统
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Experimental investigations on wear properties of Palm kernel reinforced composites for brake pad applications
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作者 Satish Pujari S.Srikiran 《Defence Technology(防务技术)》 SCIE EI CAS CSCD 2019年第3期295-299,共5页
The use of asbestos material is being avoided to manufacture the brake pads as it is harmful and toxic in nature. Further it leads to various health issues like asbestosis, mesothelioma and lung cancers. These brake p... The use of asbestos material is being avoided to manufacture the brake pads as it is harmful and toxic in nature. Further it leads to various health issues like asbestosis, mesothelioma and lung cancers. These brake pads can be replaced by natural fibers like Palm kernel (0-50%), Nile roses (0-15%) and Wheat (0-10%) with additives like aluminum oxide (5%-20%) and graphite powder (10%-35%). Phenolic resin of 35% is utilized as a binder. Particulated Nile roses are used to increase the friction coefficient and wheat powder is used to reduce the wear rate. Aluminum oxide and graphite are abrasive in nature. This helps to make brake pads with high friction co-efficient and less wear rate with low noise pollution. The wear of the proposed composites have been investigated at different speeds. Various tests like wear on pin-ondisc apparatus, hardness on the Rockwell hardness apparatus and oil absorption test have been conducted. Phenolic resin produces good bonding nature to fiber. Thus, Fibers found to have performed palatably among all commercial brake pads. The objective of the research indicates that Palm kernal shell could be a conceivable alternative for asbestos in friction coating materials. 展开更多
关键词 Friction materials PALM KERNEL fiber NILE ROSE Wheat brake pad WEAR TEST Hardness TEST Oil absorption TEST
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Analysis and Design of Circular Plate MR Fluids Brake
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作者 Yang Yan Lin Chang-Hua Li Hui Zhou Jing 《上海交通大学学报》 EI CAS CSCD 北大核心 2004年第z2期152-154,共3页
A magnetorheological (MR) fluids brake is a device to achieve brake by shear force of MR fluids. A MR rotary brake has the property that its braking torque changes quickly in response to an external magnetic field. In... A magnetorheological (MR) fluids brake is a device to achieve brake by shear force of MR fluids. A MR rotary brake has the property that its braking torque changes quickly in response to an external magnetic field. In this study, the design method of the circular plate MR fluids brake is investigated theoretically. The equation of the torque transmitted by the MR fluids in the brake is derived to provide the theoretical foundation in the design of the brake. Based on this equation, after mathematically manipulated, the calculations of the volume, thickness and width of the MR fluids within the circular plate MR fluids brake are yield. 展开更多
关键词 MR FLUIDS brake DESIGN METHOD
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Assessing performance of collision mitigation brake system in Chinese traffic environment 被引量:5
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作者 ZHAO Zhi-guo ZHENG Xun-jia +2 位作者 WANG Jian-qiang XU Qing KODAKA Kenji 《Journal of Central South University》 SCIE EI CAS CSCD 2019年第10期2854-2869,共16页
Advanced driver-assistance systems such as Honda’s collision mitigation brake system(CMBS)can help achieve traffic safety.In this paper,the naturalistic driving study and a series of simulations are combined to bette... Advanced driver-assistance systems such as Honda’s collision mitigation brake system(CMBS)can help achieve traffic safety.In this paper,the naturalistic driving study and a series of simulations are combined to better evaluate the performance of the CMBS in the Chinese traffic environment.First,because safety-critical situations can be diverse especially in the Chinese environment,the Chinese traffic-accident characteristics are analyzed according to accident statistics over the past 17 years.Next,10 Chinese traffic-accident scenarios accounting for more than 80%of traffic accidents are selected.For each typical scenario,353 representative cases are collected from the traffic-management department of Beijing.These real-world accident cases are then reconstructed by the traffic-accident-reconstruction software PC-Crash on the basis of accident-scene diagrams.This study also proposes a systematic analytical process for estimating the effectiveness of the technology using the co-simulation platform of PC-Crash and rateEFFECT,in which 176 simulations are analyzed in detail to assess the accident-avoidance performance of the CMBS.The overall collision-avoidance effectiveness reaches 82.4%,showing that the proposed approach is efficient for avoiding collisions,thereby enhancing traffic safety and improving traffic management. 展开更多
关键词 active-safety technology effectiveness assessment accident reconstruction autonomous emergency braking PC-CRASH
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轮毂电动机驱动车辆并联式复合制动策略 被引量:2
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作者 付翔 肖帅 徐超 《江苏大学学报(自然科学版)》 CAS 北大核心 2025年第1期9-17,共9页
基于并联式轮毂电动机驱动实车构型,分析影响制动能量回收效率的主要因素,采用联邦卡尔曼滤波纵向车速估计算法,提出了三层式复合制动控制策略.该策略中的制动决策层根据踏板输入信号和行驶状态来识别制动工况,并进入相应的制动模式.制... 基于并联式轮毂电动机驱动实车构型,分析影响制动能量回收效率的主要因素,采用联邦卡尔曼滤波纵向车速估计算法,提出了三层式复合制动控制策略.该策略中的制动决策层根据踏板输入信号和行驶状态来识别制动工况,并进入相应的制动模式.制动控制层根据制动决策层的指令,在常规制动工况下通过粒子群优化(PSO)算法优化前、后轮电制动力矩分配,实现电池有效回收效率最大化;紧急制动工况下,通过模糊自整定PID算法实现车辆在不同附着路面上各轮滑移率的安全有效控制,优化了制动防抱死控制的鲁棒性,提高制动安全性.制动执行层响应制动控制层的指令,设计了电制动补偿机制,以迅速补偿调节各轮轮缸的压力误差,提高车辆制动稳定性.最后实车验证了该复合控制策略的有效性. 展开更多
关键词 轮毂电动机驱动车辆 并联式复合制动 粒子群优化 制动能量回收 模糊自整定PID
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电动汽车多参数模型预测制动能量跟踪策略 被引量:1
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作者 张巍 高妍 张红娟 《汽车技术》 北大核心 2025年第1期20-25,共6页
针对电机制动能量回收率低和直流母线电压波动大的问题,提出了考虑电机功率、双向DC/DC变换器效率、超级电容电压等多个参数实时调整超级电容电流参考值的制动能量跟踪策略。采用储能单元的离散状态空间模型预测超级电容的电流和电压,... 针对电机制动能量回收率低和直流母线电压波动大的问题,提出了考虑电机功率、双向DC/DC变换器效率、超级电容电压等多个参数实时调整超级电容电流参考值的制动能量跟踪策略。采用储能单元的离散状态空间模型预测超级电容的电流和电压,并结合系统中多个参数计算超级电容的电流参考值。使用基于比例积分(PI)的电流环控制超级电容电流实时跟踪参考值,实现超级电容对电机能量的跟踪。通过仿真分析和对比试验,结果表明:所提出的策略能够将制动能量的回收效率由55.93%提升至86.76%,直流母线的电压波动范围抑制在0.9%以内。 展开更多
关键词 状态空间模型 双向DC/DC 变换器 制动能量跟踪
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应用自抗扰控制的车辆制动力优化分配策略 被引量:1
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作者 李忠利 杨雯皓 +1 位作者 闫祥海 谭志华 《重庆理工大学学报(自然科学)》 北大核心 2025年第8期69-75,共7页
为改善汽车在弯道刹车情况下的操控安全性,本研究提出一个制动力优化控制策略。设计基于横摆角速度控制的自抗扰控制器(active disturbance rejection control,ADRC),计算所需的额外横摆力矩,并利用最优化算法求解各车轮理想的制动力。... 为改善汽车在弯道刹车情况下的操控安全性,本研究提出一个制动力优化控制策略。设计基于横摆角速度控制的自抗扰控制器(active disturbance rejection control,ADRC),计算所需的额外横摆力矩,并利用最优化算法求解各车轮理想的制动力。采用CarSim/Simulink进行联合仿真,与制动力固定比例分配策略对比验证。结果表明:紧急转弯制动工况下,相比于制动力固定比例分配,ADRC控制器制动力优化分配策略在车速90 km/h,制动强度z=0.7时,横摆角速度仍能有效跟随,避免车辆失稳;制动强度z=0.3时,横摆角速度最大偏差数值可减少0.04367 rad/s,质心侧偏角最大偏差可降低0.58246°,车身侧滑情况显著改善,整体操纵稳定性得到显著提升。 展开更多
关键词 汽车动力学 自抗扰控制 制动力优化分配 弯道制动
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不同驾驶循环制动工况下刹车颗粒物排放特性研究 被引量:2
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作者 葛蕴珊 谢汶峰 +4 位作者 李家琛 马尧 王宇 王亚超 王昌钰 《北京理工大学学报》 北大核心 2025年第4期402-408,共7页
为探究基于制动惯性实验台的不同驾驶循环刹车颗粒物排放特性,在密封采样仓内分别进行WLTC循环和US06循环等效制动排放试验,测量了10 nm~10μm粒径范围的刹车颗粒物排放.研究发现多次US06循环测试中,每次循环前四次工况排放的100 nm粒... 为探究基于制动惯性实验台的不同驾驶循环刹车颗粒物排放特性,在密封采样仓内分别进行WLTC循环和US06循环等效制动排放试验,测量了10 nm~10μm粒径范围的刹车颗粒物排放.研究发现多次US06循环测试中,每次循环前四次工况排放的100 nm粒径以上的颗粒物数量结果重复性差,且行程动力学参数(v·a)增大会导致所有粒径的颗粒物生成数量的稳定性变差;100 nm粒径以上颗粒物对刹车颗粒物质量浓度的贡献大,而刹车颗粒物数量浓度排放则更多由10~100 nm小粒径颗粒物决定.研究还发现颗粒物的生成与工况的加速度和速度密切相关,在车辆实际驾驶中,较高的行驶速度以及较大的刹车加速度都会促进100 nm以下小粒径颗粒物生成,而100 nm以上大颗粒的生成主要受到较大刹车加速度的影响,保持车速低于100 km/h、加速度低于2 m/s^(2)生成的大、小粒径颗粒物较少.对比US06循环和WLTC循环的高速度段与超高速段颗粒物排放数据,制动工况更为激烈的US06循环倾向于生成更多大粒径颗粒物,而WLTC循环超高速度段在小粒径颗粒物生成上更为显著. 展开更多
关键词 制动颗粒物 驾驶循环制动工况 颗粒物数量 颗粒物质量 粒径分布
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基于交通事故数据驱动的乘用车AEB高速公路测试场景构建 被引量:1
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作者 刘永涛 刘永杰 +2 位作者 朱屹晨 惠志强 赵晨 《汽车技术》 北大核心 2025年第6期15-22,共8页
为了提升乘用车自动紧急制动系统(AEB)测试场景的效能,基于中国交通事故深度研究(CIDAS)数据库中183起交通事故案例,探究高速公路AEB系统测试场景构建。从CIDAS数据库中选取静态与动态因素作为聚类参数,使用K均值聚类方法对事故数据进... 为了提升乘用车自动紧急制动系统(AEB)测试场景的效能,基于中国交通事故深度研究(CIDAS)数据库中183起交通事故案例,探究高速公路AEB系统测试场景构建。从CIDAS数据库中选取静态与动态因素作为聚类参数,使用K均值聚类方法对事故数据进行初步分类,根据聚类结果得到了5类典型事故场景,在此基础上参考现有测评标准,设计了5类乘用车AEB系统的高速公路测试场景,为AEB系统的开发与优化提供参考。 展开更多
关键词 交通事故 数据驱动 K 均值聚类 自动紧急制动系统 测试场景构建
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制动位置对重载列车纵向动力响应的影响 被引量:2
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作者 龚凯 杨泽宇 +2 位作者 卞文君 罗江铃 张洪 《中南大学学报(自然科学版)》 北大核心 2025年第6期2597-2610,共14页
为研究重载铁路货物列车在组合坡段区域起始制动位置对其纵向动力响应的影响,基于列车纵向动力学理论,采用多体动力学仿真软件UM构建列车纵向动力学仿真模型,实现货物列车的制动全过程计算。通过研究货物列车在制动过程中纵向车钩力、... 为研究重载铁路货物列车在组合坡段区域起始制动位置对其纵向动力响应的影响,基于列车纵向动力学理论,采用多体动力学仿真软件UM构建列车纵向动力学仿真模型,实现货物列车的制动全过程计算。通过研究货物列车在制动过程中纵向车钩力、纵向加速度以及制动位移响应的影响,得出重载列车在不同起始制动位置进行制动时的纵向动力响应变化规律。研究结果表明:对于10000~30000 t载重的重载列车,当列车在经过变坡点后分别行驶至列车全长的1/5、1/4和1/3位置时开始制动,此时列车纵向车钩力将达到峰值,表明这些制动起始位置对列车纵向动力响应的影响最大;当10000~30000 t不同载重的重载列车在经过变坡点后行驶距离分别不超过50、150和250 m时开始制动,此时列车纵向车钩力最小,行驶速度最快,在此处进行制动对列车纵向动力响应影响最小,运输效益最佳。同时,随着制动起始位置逐渐靠近列车尾部,列车实现完全制动所需的距离显著缩短;增加列车载重会减小列车制动距离差,从而延长列车完全制动所需的时间。 展开更多
关键词 重载铁路 货物列车 制动位置 纵向车钩力 纵向加速度
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